1. Technical Field
The present disclosure relates to a complex for detecting a target material and a method of detecting a target material using the same. More specifically, the present disclosure is directed to a complex for detecting a target material comprising upconverting nanoparticles (UCNPs) excited by a near infrared (NIR) light source and a target material specific aptamer-quencher, a method of preparing the same, a kit for detecting a target material comprising the same, and a method of detecting a target material using the same.
2. Description of the Related Art
Recently, detecting a target material such as mycotoxins present in a sample has been emerging as an important issue.
One of the mycotoxins of these target materials is Ochratoxin A (OTA). OTA is a mycotoxin that is produced by several fungal strains of Aspergillus and Penicillum genera, and primarily exists in for example coffee, grains, legumes, wine, grape juice, and the like. OTA has been reported not to be destroyed by cooking process such as a common heat treatment, but has a chemical stability and long half-life and induces DNA damages and chromosomal abnormalities. OTA has been classified by the International Agency for Research on Cancer as being a possible carcinogen in humans with the characteristics of teratogenicity, carcinogenicity, immune toxicity, hepatotoxicity, etc. (Group 2B). Due to potential risks to human health and possible contaminations of various foods, many countries enacted a regulatory limit for the levels of OTA for specific foods, and several research efforts have been conducted to develop sensitive methods for OTA detection.
Standard detection method according to the Association of Official Agricultural Chemists (AOAC) includes a high-performance liquid chromatography (HPLC). Although this method provides a high sensitivity, since it has to undergo processes including washings or analysis such as by extraction, cartridge and/or immune-affinity column, the detection process is complicated, and thereby requires a specialist and takes a long time in analysis, as well as costs high. As an alternative to overcome these drawbacks, there includes an enzyme immunoassay (ELISA) and a lateral flow immunoassay (LFA). However, the ELISA frequently causes a used antibody to be cross-reactive with materials similar to the Ochratoxins, and therefore the accuracy is poor. Thus, the ELISA has not yet been used as an internationally recognized method (AOAC). Further, with the ELISA and LFA, it is not easy to acquire antibodies for detecting a low molecular material, Ochratoxins, and since they receive a negative signal by an immune response through a competitive reaction, the sensitivity is not good. In particular, when applying to a real food sample, homogeneous detection of OTA is limited due to a matrix effect caused by by-products in various foods.
Additionally, methods of using a biosensor based on fluorescence resonance energy transfer (FRET) are disclosed. According to the FRET method, it is advantageous that a combination of a target material can be measured in a homogenous state without a washing process. However, it is problematic that biomolecules may be damaged by UV or visible light used to excite organic fluorescent materials and quantum dots, and non-specific signals may be caused by matrix effects due to different by-products discharged from samples.